DevShed continues their "loaders in applications" series with this fourth part, a look at including files recursively.

This series uses a variety of code samples to teach you how to create modular programs. These programs are capable of recursively including files required by a given application, without having to explicitly call any "include()/include_once()" or "require()/require_once()" PHP function.

In their example they show how to use their loader class (built up from previous parts of the series) and modify it slightly to allow the script to set the file path, set the files to include and pull them in.